RJ45 connections

rrjwilson

New member
I have a cunning plan for a friend and I to play games on ethernet without wireless but it means some fun. I have the electronic knowledge to build my plan but I don't know enough about how network traffic goes through the cable to do my design (if its even possible).

Ethernet use the PHY to convert to digital signal over the wires and at the other end the PHY turns the digital signal back into meaningful data for the other computer. Digital signals as even my Gran will tell you is 1 and 0 or more importantly Ons and Offs. This is where my knowledge goes south, the cable has 8 smaller cables in it, 4 colours with + and - types (ie solid and spiral coloured). As far as I am aware only 4 wires are actually used during communication. So this is the part I don't know. The wires run in pairs which mean that they are either paired as signal and ground or send and receive. For two way communication there must be signals going both ways so either is plausible but having no ground and send and receive pairs seems the most likely as digital signal won't need a reference voltage (ground) because of its nature.

Can anyone shed light upon this?

I had an idea to find out but I figured its probably easier to ask first than build a large electronic tester. LEDs only allow current in one direction so if i build a pass-through box and change the LED configuration until I get a working system.

Unfortunately this relies on this principle that communication is one way on a single wire, which also needs confirmation.
 
Yes of course I can play over a 400m ethernet cable :mad:

I said I wanted confirmation on the telecommunications technology not suggestions that were not asked for. If you do not understand then you cannot answer but maybe you know someone or somewhere the answer can be found.
 
name='rrjwilson' said:
Yes of course I can play over a 400m ethernet cable :mad:

I said I wanted confirmation on the telecommunications technology not suggestions that were not asked for. If you do not understand then you cannot answer but maybe you know someone or somewhere the answer can be found.

and an attitude like that, nobody will attempt to help you...
 
name='rrjwilson' said:
Yes of course I can play over a 400m ethernet cable :mad:

I said I wanted confirmation on the telecommunications technology not suggestions that were not asked for. If you do not understand then you cannot answer but maybe you know someone or somewhere the answer can be found.

You can't use a 400m ethernet cable, max run length is 100meters. So you would require 4 bridge/switch devices.

Please do explain what you want in a little MORE depth, as ethernet is very different to telecommunications.
 
I have already explained the wiring information I require but here goes again.

Out of the 8 wires in an Ethernet cable, only 4 wires are used, these 4 wires are actually 2 pairs. The pairs are green and orange. In each pair there is what is referred to as + and - wires.

Usually the spiralled colour wire is referred to as the + wire for that pair, thereby making the solid colour wire the - wire. This is where my question stems from.

Are the + and - wires and signal and ground respectively or are they both signal lines but one is transmit and other receive (ie + transmit and - receive)?

I have found information regarding the wiring stating that the green pair is for transmission and the orange pair is for receive. This still doesn't help my situation as the signal direction has not been given. Clearly over a single wire the direction of signals can be only one way but what way is it for the four wires?

In a crossover cable the transmit and receive lines change round (obviously). Are the only wires used for communication the + ones and with the - ones acting as just ways to complete the circuit rather than carrying information?

Knowing the answers mean i can build an ethernet device that should send data across several hundreds meters once aligned.
 
ha with your attitude you can a)stick you head up your ass, if its not already up there and toodle off

b) revise that an attitude like that doesnt help this forum at all

c)realise that maybe what your asking maybe wasnt clear enough or b you might want to try a forum more suited to networking for such a complex scenario.

*flicks a finger*

good luck with what ever your trying to do
 
o and because im feeling nice, when it comes to eternet wiring it doesnt matter what colour pairings you use as long as the pairs are the same at each end. afaik
 
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